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Ganglion of Impar Block

Patient information A-Z

What is a ganglion of impar block?

The ganglion of impar is the meeting point of the two sides of the pelvic sympathetic nerves, at the junction between the sacrum and the coccyx.

A ganglion of impar block is an injection of local anaesthetic and steroid around the nerves supplying the coccyx (or tailbone) area.

Before the procedure

  • You will have treatment as an outpatient at the Ely Day Surgery Unit.
  • Your stay may be between two to four hours. Before any treatment begins you will be asked to provide assurance that someone is able to drive you home.
  • You will be asked to change into a theatre gown and your blood pressure and pulse will be recorded. Your doctor will then discuss the procedure with you and ask you to sign a consent form.

The procedure

This information leaflet is to be read in conjunction with the leaflet titled ‘Advice to be read before your Pain Clinic injection treatment’.

  • In the treatment room, you may have a small needle (cannula) placed in the back of your hand. This allows the doctor to give you sedation if necessary.
  • Once you are lying in the correct position, the doctor will clean the area with an antiseptic solution which can feel very cold.
  • Local anaesthetic and steroid is then injected into the area which may briefly cause some discomfort but the area will soon go numb.

After the injection

  • You will be taken to the recovery area where the nursing staff will observe you.
  • You may feel a little drowsy and wish to sleep.
  • You will remain lying down for 30 minutes and then be assisted to sit up. We will offer you some light refreshment.
  • Your blood pressure and pulse will be checked frequently.
  • Before you leave, the doctor/nurse will ask a few questions about your pain and any effects that the injection may have had.

Please ensure that you have arranged for someone to drive you home after this procedure. Failure to do so will result in your procedure being cancelled.

If you have had sedation, we recommend that you arrange for someone to stay with you overnight and that you do not drive for 24 hours.

Possible side effects / risks

  • Unfortunately, no procedure is risk free.
  • Although long term side effects and complications are uncommon, they can occur.
  • Infection is a theoretical risk but very rare.
  • You may have mild local tenderness at the site of the injection(s), which will usually settle over the next few days.

What to expect afterwards

  • Some rapid relief of your pain may be noticed due to the local anaesthetic. It could take several days before the steroid becomes effective.
  • Take your regular pain killers as normal.
  • If this injection relieves your pain please remember that it is not a cure. Do not do strenuous activities immediately, but build up your activity level slowly.
  • Simple activities like a daily walk or swimming will help to improve your muscle tone. The best way is to increase your activity slowly.

Follow up

You will be sent an appointment to attend the pain clinic two to eight weeks following your treatment to review the effects of the injection.

Points to remember

  • Please bring your glasses if you need them for reading.
  • Always bring a list of all current medications.
  • Continue taking all your usual medication on treatment day, unless you have been contacted and advised otherwise.
  • If there is any possibility you may be pregnant please inform the doctor or nurse.

Additional information

The information in this leaflet is not intended to replace your doctor’s advice. If you require more information or have any questions please contact your GP or the Pain Clinic Monday to Friday 13.30- 16.30.

We are smoke-free

Smoking is not allowed anywhere on the hospital campus. For advice and support in quitting, contact your GP or the free NHS stop smoking helpline on 0800 169 0 169.

Other formats

Help accessing this information in other formats is available. To find out more about the services we provide, please visit our patient information help page (see link below) or telephone 01223 256998.

Contact us

Cambridge University Hospitals
NHS Foundation Trust
Hills Road, Cambridge

Telephone +44 (0)1223 245151